1. Field of the Inventive concept
Example embodiments of the inventive concepts relate to a semiconductor device.
2. Description of the Related Art
A memory system may include a memory device and a memory controller, the memory device and the memory controller being connected to each other by a transmission line transferring a signal. In general, the transmission line is terminated with a set voltage level for a stable signal transfer. Termination schemes may include a Center Tap Termination (CTT) scheme and a High Tap Termination (HTT) scheme.
In the CTT scheme, a scheme of terminating a transmission line with half of a power voltage, a termination resistor may be connected between a power voltage source and a center node in parallel therewith and another termination resistor may be connected between the center node and a ground in parallel therewith. However, due to a mismatch in a process, a resistance value of the termination resistor between the power voltage source and the center node and a resistance value of the termination resistor between the center node and the ground may be varied.
An eye pattern may be used to evaluate a data transmission using an oscilloscope to display received data bits in synchronization with a clock signal. In the data transmission, rectangular edges between “1” and “0” states may appear rounded due to unwanted jitter and phase distortion, thus forming an eye pattern. Therefore, when the aperture of the eye pattern is wider, the data transmission may have a better signal quality. However, due to the mismatch between the resistance values, the eye aperture of a corresponding semiconductor device may not have symmetrical characteristics. When a plurality of semiconductor devices are simultaneously used, characteristics in which eye apertures of the respective devices are overlapped with each other, that is, eye aperture characteristics of the entire semiconductor device, may be deteriorated.
Thus, demand for solutions capable of improving the eye aperture characteristics has been increasing.